How do I block these bots in httpd.conf?

ReWriteCond problem

[superclown2]

I'm being driven crazy trying to block some bots. I can do it using .htaccess but I'd rather use httpd.conf because there's much less server load. What I've got is:
RewriteEngine on
RewriteCond %{HTTP_REFERER} ^Larbin [NC,OR]
RewriteCond %{HTTP_REFERER} ^veryprivate* [NC]
RewriteRule .* - [F]

I've tried this in the body of httpd.conf and between <virtualhost> and </virtualhost> but they still appear in my logs and the rewrite log remains empty. I've set the rewrite module to load. Any suggestions would leave me eternally grateful!

[mlewitz]

This is the EXACT same problem I'm going through.

Here's my post from just YESTERDAY.

[webmasterworld.com ]

-Mike